title: A novelty seeking phenotype is related to chronic hypothalamic-pituitary-adrenal activity reflected by hair cortisol.
abstract: Reduced hypothalamic pituitary adrenal (HPA) activity is associated with greater novelty seeking in humans. Hair cortisol represents an integrated proxy measure of total cortisol production/release over an extended period of time and may be a valuable tool for tracking the HPA system. Sampling approaches (collection of blood, saliva, urine, or feces) for socially housed nonhuman primates present a number of technical challenges for collection particularly when repeated sampling is necessary. Herein we describe a relationship between cortisol levels measured in hair collected from 230 socially housed female vervet (Chlorocebus aethiops sabaeus) monkeys and a free-choice novelty seeking phenotype. A predator-like object was placed at the periphery of the outdoor enclosures for 30 min and speed of approach (latency to approach within 1m) and persistence of interest (number of 1 min intervals within 1m) were scored. A composite Novelty Seeking score, combining these two measures, was calculated. The intra-class correlation coefficient (ICC=.68) for two different objects across years indicated that this score reflects a stable aspect of temperament. Hair samples were collected from each subject approximately 3-6 months following the second assessment; cortisol levels were determined from the hair. A significant inverse relationship of Novelty Seeking score with hair cortisol level (p<.01) was noted. The high hair cortisol groups had significantly lower Novelty Seeking scores than the low cortisol groups both years (p's<.05). These results suggest that low average cortisol levels promote novelty seeking, while high average levels inhibit novelty seeking behavior.
authors.affiliation: Department of Psychiatry, University of Colorado at Denver School of Medicine, Denver, CO 80220, USA. mark.laudenslager@ucdenver.edu
authors.forename: Mark L
authors.initials: ML
authors.lastname: Laudenslager
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Jorgensen
authors.forename: Rachel
authors.initials: R
authors.lastname: Grzywa
authors.forename: Lynn A
authors.initials: LA
authors.lastname: Fairbanks
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D002522:Chlorocebus aethiops; D002851:Chromatography, High Pressure Liquid; D005106:Exploratory Behavior / Q000502:physiology*; D005260:Female; D006197:Hair / Q000378:metabolism*; D006854:Hydrocortisone / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology*; D008137:Longitudinal Studies; D010641:Phenotype; D010913:Pituitary-Adrenal System / Q000502:physiology*; D013223:Statistics as Topic; D013997:Time Factors
chemical_list: D006854:Hydrocortisone